1. Field of the Invention
The present invention generally relates to the field of electrical connectors and more particular to an electrical connector for connecting a Flexible Printed Circuit (FPC).
2. The Related Arts
An FPC (Flexible Printed Circuit) connector connects a flexible printed circuit to a regular printed circuit board. The FPC connector comprises a housing defining a central slot and conductive contacts retained in the housing with opposite branches thereof arranged on opposite sides of the slot. The housing is mounted to a printed circuit board and the contacts are soldered to the printed circuit board. A stuffer bar is partially and movably received in the slot. The stuffer bar has a flat face on which an end of a flexible circuit is positioned. The stuffer bar is then moved further into the slot of the housing, securely fit between the opposite branches of the contacts. This applies a normal force to the flexible circuit, driving the flexible circuit against the contacts thereby engaging conductive pattern of the flexible circuit with the contacts. The stuffer bar must be mechanically strong to stand friction force induced by the normal force between the flat face thereof and the flexible circuit in order to properly move with respect to the housing. An example is shown in U.S. Pat. No. 5,308,262.
With the miniaturization of electronic parts, the stuffer bar is made smaller and thinner, while the number of contacts of the FPC connector in a given length is increased. The increased number of contacts leads to large friction. Thus a greater driving force is required for moving the stuffer bar into/out of the slot to engage/disengage the flexible circuit with/from the contacts. In moving the stuffer bar our of the slot, such a large friction force may make a central portion of the stuffer bar stuck in the connector housing, while opposite end portions of the stuffer bar that are gripped by fingers of a user are moved outward already. This bends the stuffer bar and may eventually break the stuffer bar.
In addition, in moving the stuffer bar and the flexible circuit into the housing of the connector, such a great force may prevent the stuffer bar from being correctly inserted into the slot. Thus, proper engagement between the conductive pattern of the flexible circuit and the contacts of the connector may not be obtained.
Further, such a situation can be worse with the dimension of the stuffer bar reduced. The thinner the stuffer bar is, the worse the situation can be.
It is thus desirable to provide an FPC connector with a modified stuffer bar to overcome the above problems.
Accordingly, an object of the present invention is to provide an FPC connector comprising a stuffer bar requiring less insertion force.
Another object of the present invention is to provide an FPC connector comprising a stuffer bar capable to alleviate undesired deformation thereof during engagement with and/or disengagement from a flexible circuit.
To achieve the above objects, an FPC (Flexible Printed Circuit) connector constructed in accordance with the present invention comprises a housing defining a central slot and conductive contacts having opposite branches retained in the housing on opposite sides of the central slot. A stuffer bar is received in the central slot and is movable between a withdrawn position and an engaged position. The stuffer bar has finger grips on opposite ends thereof for being gripped by fingers of a user to apply a driving force to move the stuffer bar with respect to the housing. The stuffer bar has a flat surface on which a flexible circuit is positioned whereby when the stuffer bar is moved to the engaged position, a normal force is applied by the flat surface of the stuffer bar to the flexible circuit for engaging a conductive pattern of the flexible circuit with the corresponding contacts. A recess is formed in a middle portion of the flat surface of the stuffer bar whereby the middle portion of the stuffer bar is free of normal force acting upon the flexible circuit. The total force acting upon the flexible circuit is divided into two components acting on opposite sides of the recess and located close to the finger grips thereby reducing moments induced by the driving force. Damage caused by undue deformation of the stuffer bar is thus alleviated.